Combustors are commonly used in industrial and power generation operations to ignite fuel to produce combustion gases having a high temperature and pressure. For example, turbo-machines such as gas turbines typically include one or more combustors to generate power or thrust. A typical gas turbine includes an inlet section, a compressor section, a combustion section, a turbine section, and an exhaust section. The inlet section cleans and conditions a working fluid (e.g., air) and supplies the working fluid to the compressor section. The compressor section progressively increases the pressure of the working fluid and supplies a compressed working fluid to the combustion section. A fuel is mixed with the compressed working fluid within the combustion section and the mixture is burned in a combustion chamber defined within the combustion section to generate combustion gases having a high temperature and pressure. The combustion gases flow to the turbine section where they expand to produce work. For example, expansion of the combustion gases in the turbine section may rotate a shaft connected to a generator to produce electricity.
The combustion section may include one or more combustors annularly arranged between the compressor section and the turbine section. In a particular combustor design, the combustors include one or more axially extending bundled tube fuel injectors disposed downstream from an end cover. The end cover generally includes one or more fuel circuits that provide fuel to a fluid conduit that provides for fluid communication between the fuel circuits and a fuel plenum defined within each bundled tube fuel injector. Each bundled tube fuel injector generally includes a plurality of parallel tubes arranged radially and circumferentially across the bundled tube fuel injector. The parallel tubes extend generally axially through the fuel plenum to provide for fluid communication through the fuel plenum and into the combustion chamber. The compressed working fluid is routed through inlets of each of the parallel tubes. Fuel is supplied to the fuel plenum through the fluid conduit and the fuel is injected into the tubes through one or more fuel ports defined within each of the tubes. The fuel and compressed working fluid mix inside the tubes before flowing out of the tubes and into the combustion chamber for combustion.
Typically, one end of the fluid conduit is rigidly bolted to the end cover and a second end is fixedly or rigidly connected to the bundled tube fuel injector, thereby creating an end loaded cantilevered mass. As a result, the fluid conduit generally carries the majority of the load created by the cantilevered bundled tube fuel injector at the end cover and fluid conduit connection.
The bundled tube fuel injector is typically heavier or has a greater mass than a conventional fuel nozzle structure which may also be cantilevered. As the combustor cycles through various operating modes, the cantilevered bundled tube fuel injector may vibrate at various frequencies which may result in large deflections of the fluid conduit, thereby causing undesirable bending stresses at the end cover and fluid conduit connection. Therefore, an improved system for mounting and/or supporting a bundled tube fuel injector within a combustor would be useful.